We want to make procedural generation as accessible as possible. Just like a movie director who shows a portfolio of photos and concept art to the CGI team and just says "make it look like this", we wanted the creator to be entirely clueless about how everything works.
This is how it feels to create a new terrain type. You provide a few pictures of it and we take it from there:
This system builds a probabilistic model based on the samples you provide. That is enough to get an idea of the base elevation. On top of that, several natural filters are applied. It turns out we do know a bit more about this landscape. We know how dry it is, what is the average temperature among other things. The only fact we are missing and have to ask about is how old do you think this is. The time scales range from hundreds of millions of years to billions of years. (If you believe your terrain is 6000 years old we cannot accommodate you at the moment.)
You can provide one or more sample pictures. The more pictures you provide, the better, but just one picture is often enough. Ready to see some results? The following terrains were synthesized out of a single photo in every case (do not mind the faux coloring, this is only to indentify the different terrain layers for now):
Providing multiple samples creates some sort of mix, similar to how you find both mother and father features in their kids:
The natural filters in this case added some realism to the concept, and eroded some of the original hill shape. This could be avoided if you are after a more stylized look. But if you are short on time, and want to prototype different realistic terrains, the ability to quickly sketch something and feed it to the generator is a big help.
Of course you can still look under the hood and tinker with generation frequencies, filter parameters, etc. You can still have terrain models imported from Digital Elevation Models, or from third party software like World Machine. The key here is you do not have to anymore.
I'd be glad to enter into details of how this works if you guys are interested. Just let me know. I still owe the Part 2 of the continent generation. That should come shortly.